The present invention relates, in general, to semiconductor devices, and more particularly, to methods of forming silicon carbide semiconductor devices.
In the past, a variety of methods have been utilized to form silicon carbide junction field effect transistors (JFETs). However, with these prior methods it is difficult to obtain accurate registration between the gate contact and the gate material.
Additionally, the very high temperatures required to form source and drain contacts, typically greater than 900.degree. C., generally requires that gate contacts be applied after the source and drain contact annealing. Consequently, source and drain contacts typically have some misalignment to the source and drain areas. Additionally, extra distance must be provided between the gate and the source and drain areas in order to prevent shorts therebetween, thus, the resulting transistor has a large size and degraded device performance.
Accordingly, it is desirable to have a method of forming a silicon carbide JFET that provides source and drain contacts that are self-aligned to the source and drain areas, that provides for annealing of the source and drain contacts prior to forming the gate contact, and that provides a gate contact that is self-aligned to the gate area.